This coin is only about 10mm in diameter but the illustrations are greatly enlarged. It was unearthed by John Lashmar, who asked for an ID and a valuation.
The coin is a class IIIg London farthing .of Edward I. On the obverse the legend reads E R AnGLIE around the bust of King Edward. On the reverse the legend reads LON DON IEN SIS. In the Standard Catalogue the type is listed as number 1446.
There is a weak area on both sides but the coin is otherwise in near VF condition and is nicely toned. Pricewise, I’d say around £70.